Copper Solders

High-performance copper solder tailored to your process

Discover our precise, customizable copper solders for robust and repeatable performance.

Copper solder is the material of choice when durable, thermally stable and conductive metal bonding is essential. Whether you’re working with steels, stainless steels, nickel or copper/nickel alloys – its corrosion resistance, excellent formability and superior wetting properties make it a versatile solution across industries.

At LOT-TEK, we engineer copper solder alloys to match exact process needs – from high-purity variants for vacuum brazing to formulations that perform flawlessly under inert gas or even open flame conditions. For operations requiring minimal oxide formation, phosphorus-based copper solders act simultaneously as a reducing agent and integrated flux.

If mechanical strength is your top priority, zinc-containing copper solder delivers – provided it’s not overheated, as excess heat may cause zinc evaporation. We also offer copper solder alloys designed specifically for high-temperature brazing applications, where thermal resistance and joint longevity are non-negotiable.

Our product overview showcases our full portfolio of copper solder options. You can also learn more about the industries we serve or get in touch directly through our contact page to discuss your project requirements.

Product overview: Copper Solders

ProduktCompositionISO / UNS AWSSolidus [°C]Liquidus [°C]
CDA 10199.99Cu– / – BVCu-1x10831083Anfragen
BCu-199.9CuCu 141 / C11000 BCu-110831083Anfragen
Copperhead 12499CuCu 099 / – BCU-1a10831083Anfragen
BCu-286.5CuCu 087 / – BCu-210831083Anfragen
CDA 10299.95CuCu 102 / C10200 BCu-310831083Anfragen
CDA 11099.9CuCu 110 / C14180 BCu-1b10831083Anfragen
CDA 52191.7Cu8Sn0.3P– / – RCuSn-C8821027Anfragen
CuSn1287.8Cu12Sn0.2PCu 925 / C92501 –825990Anfragen
87.75Cu12Ge0.25Ni880975Anfragen
CB 23567.5Cu23.5Mn9Ni925955Anfragen
CDA 77348Cu41.25Zn10Ni0.5Si0.25PCu 773 / C77300 RBCuZn-D921935Anfragen
CB 38052.5Cu38Mn9.5Ni880925Anfragen
X-55 (CDA 548)55Cu34.85Zn6Ni4Mn0.15Si880920Anfragen
CB 12054.85Cu25Zn8Ni12Mn0.15Si855915Anfragen
CDA 47059Cu40.4Zn0.6SnCu 470 / C47000 RBCuZn-A888899Anfragen
CDA 68158Cu40Zn0.8Fe1Sn0.2MnCu 471 / C47100 RBCuZn-C866888Anfragen
CDA 68058Cu39.4Zn0.8Fe1Sn0.5Ni0.2Mn0.1SiCu 681 / 68100 RBCuZn-B866882Anfragen
Silver Phos 589Cu6P5AgCuP 281 / C55281 BCuP-3643813Anfragen
Silver Phos 688Cu6P6Ag643807Anfragen
Silver Phos 1580Cu15Ag5PCuP 284 / C55284 BCuP-5643802Anfragen
Phos Copper 092.75Cu7.25PCuP 181 / C55181 BCuP-2710793Anfragen
Silver Phos 291Cu7P2AgCuP 280 / C55280 BCuP-6643788Anfragen
Silver Phos 5HP88.25Cu6.75P5AgCuP 282 / C55282 BCuP-7643771Anfragen
Silver Phos 6HP86.75Cu7.25P6AgCuP 283 / C55283 BCuP-4643718Anfragen
Silver Phos 2LP91.5Cu6.5P2Ag 643704Anfragen
Tin Phos 786.8Cu6.5P6.5Sn0.2SiCuP 385 / C55385 BCuP-9637675Anfragen
Silver Phos 1876.05Cu17.6Ag6.35P CuP 285 / C55385 BCuP-8643666Anfragen
Silver Phos 18M75.75Cu18Ag6.25P643665Anfragen

Applications and Industrial Use Cases of Copper Solder

Copper solder is an essential joining material across a wide range of technical industries. Its reliability under thermal load, high conductivity and excellent wetting behavior make it especially well-suited for brazing operations in sectors where strong, thermally and mechanically stable joints are critical.

Our copper solder alloys are widely used in the automotive industry, where temperature resistance and vibration tolerance are key factors in component assembly. In the electrical engineering sector, they enable reliable conductivity in busbars, terminals and copper-based contact systems.

In aviation and aerospace, weight-sensitive components benefit from corrosion-resistant copper joints that perform under extreme pressure and temperature changes. Copper/nickel and stainless steel connections are also commonly realized using our copper solder alloys in medical device manufacturing.

In high-voltage systems, vacuum tubes, sensors and power electronics, brazing under vacuum or inert gas plays a major role. For these applications, LOT-TEK offers high-purity copper solder grades that ensure flux-free operation and metallurgical cleanliness. Read more about vacuum brazing applications on our dedicated page.

Wherever strong metal bonds are required – from tool manufacturing to sensor systems – LOT-TEK copper solder alloys prove their industrial value day after day.

But what exactly sets our copper solder compositions apart? Let’s take a closer look at the key technical properties and available alloy variations.

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Technical Properties and Alloy Variations

Not all copper solder is created equal – and we make sure you get exactly what your application demands. At LOT-TEK, we offer copper-based solders engineered for dimensional accuracy, thermal reliability, and process adaptability.

Thanks to their excellent electrical and thermal conductivity, our copper alloys are ideal for heat-intensive or current-carrying connections. High formability ensures easy handling, even in geometrically complex brazing areas, while strong wetting characteristics lead to smooth, consistent joints with minimal porosity.

We offer a variety of copper solder alloys to meet specific technical demands:

  • High-purity copper solders – perfect for vacuum brazing, where flux-free processes are required.
  • Phosphorus-containing copper alloys – serve as both filler metal and active flux when joining pure copper or copper-based materials.
  • Zinc-containing copper solders – deliver high mechanical strength, ideal for dynamically stressed joints; just avoid excessive heat to prevent zinc evaporation.
  • High-temperature copper solder variants – designed for use in elevated-temperature environments such as heat exchangers or furnace components.

Whether you require minimal oxide formation or maximum joint durability – we have a solution tailored to your process and production setup.

What does this mean for real-world integration into your soldering workflow? In the next section, we’ll explore how copper solder performs in flux-based and flux-free brazing environments alike.

Process Integration and Soldering Techniques

For copper solder to reach its full potential, it must be applied under optimal process conditions. That’s why we work closely with our customers to ensure seamless integration into both manual and fully automated brazing systems.

Our copper solder alloys are engineered for high repeatability, enabling precise control over flow behavior and wetting angles. Whether you are operating batch furnaces, induction brazing systems or open flame torches – the right alloy makes the difference.

In vacuum applications, high-purity copper solders allow for flux-free joining, eliminating the need for cleaning steps and reducing contamination risks. In contrast, when joining under open flame or inert gas atmosphere, flux-assisted brazing is often recommended to support capillary action and minimize oxidation at the joint interface.

Especially in zinc-containing copper solders, process control is critical. Exceeding temperature thresholds can lead to zinc vaporization, which compromises joint strength and surface finish. That’s why our experts are available to provide thermal process guidelines and alloy-specific recommendations tailored to your equipment and workpiece materials.

Whether you’re brazing small electrical contacts or heavy-duty mechanical parts, LOT-TEK delivers copper solder alloys that fit seamlessly into your production reality – with less rework, less downtime, and more consistency.

But performance is only one side of the equation. In the next section, we’ll show how quality assurance and traceability elevate your results even further.

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Quality, Consistency and Testing Standards

When it comes to copper solder, long-term reliability starts with metallurgical precision. That’s why every LOT-TEK alloy is produced with uncompromising quality control – from raw material sourcing to final inspection.

All of our copper solder alloys undergo systematic in-house testing for composition accuracy, thermal consistency and flow characteristics. This ensures that each batch meets the mechanical, electrical and thermal demands of your application – no deviations, no surprises.

To support traceability and compliance, we provide detailed documentation with every delivery, including material certificates and batch-specific analysis data. For sectors with elevated safety requirements such as medical, aerospace or power electronics, this level of documentation is not optional – it’s essential.

We also work with accredited third-party laboratories to validate key properties, such as tensile strength, conductivity and corrosion resistance, under extreme environmental conditions.

Beyond the numbers, quality at LOT-TEK means process stability, repeatability, and peace of mind in your daily operations. Whether you’re producing 100 joints or 100,000 – you get the same high level of confidence every time.

But quality is only the beginning. In the final section, we’ll show you what makes LOT-TEK the preferred copper solder partner for technical buyers across industries.

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Your Benefits with LOT-TEK Copper Solder

Choosing the right copper solder means choosing a supplier who understands your technical challenges – and solves them. At LOT-TEK, we don’t just deliver alloys. We deliver confidence, repeatability and efficiency into your joining process.

Exceptional mechanical strength and thermal resilience allow our copper solders to stand up to demanding applications, even under dynamic load or extreme temperatures.

Tailored alloy formulations ensure perfect compatibility with your base materials – whether you’re brazing steels, stainless steels, or nickel alloys.

Reliable wetting and flow behavior reduce cycle times and minimize rework – saving you time, money and production effort.

Vacuum-capable and flux-assisted options give you full process flexibility for both automated and manual applications.

Engineering expertise and personal support ensure your brazing process is optimized from day one. We stand by your side – from alloy selection to technical integration.

Let us support your project with the copper solder solution it deserves.

Contact us now to discuss your requirements or request a personalized offer.